Closed Bug 1438768 Opened 7 years ago Closed 6 years ago

Writing an email in outlook.com's web-interface is slow

Categories

(Core :: Layout, defect, P2)

Product:
Core
Component:
Layout
Version:
60 Branch
Type:
defect

Tracking

()

Status:
RESOLVED WORKSFORME
Project Flags:
Performance Impact low

People

(Reporter: linuxhippy, Unassigned, NeedInfo)

References

(Blocks 1 open bug)

Details

(Keywords: perf:responsiveness)

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0 Build ID: 20180215220507 Steps to reproduce: Logged into my outlook.com account Actual results: Typing an email somehow feels laggy. Characters appear with a small, but noticeable delay - while with other browsers they appear instantly. When I keep the backspace pressed, it seems firefox does not keep up with the key-repeat frequency and deletes a few chars even if the button is no longer pressed. The WebContent process eats up one core 100% (cust by keeping a key pressed). Firefox seems to spend a lot of time in ProcessReflowCommands (and childs): https://perfht.ml/2sASenK
Hi Mike, What do you suggest? The reporter provided the profile. Thanks
Flags: needinfo?(mconley)
Huh. This is pretty bad behaviour in the profile - we're flushing a ton because of ScrollSelectionIntoViewEvent runnables... Hey dholbert, you've touched Selection::PostScrollSelectionIntoViewEvent semi-recently... any idea what's going on here?
Flags: needinfo?(mconley) → needinfo?(dholbert)
Whiteboard: [qf]
I don't recall working with ScrollSelectionIntoViewEvent, but I don't know that it's particularly relevant, beyond the fact that it's what triggers the sync reflows here. I see a lot of nsFlexContainerFrame::Reflow in the stack, so I suspect this is a version of bug 1377253 and bug 1376536 (similar "typing is laggy" issues on Twitter & WhatsApp). Adding dependency. Bug 1393120 is also filed on other actions (mouseover) being laggy on Outlook -- I'm adding that to "See also".
Depends on: 1377253
Flags: needinfo?(dholbert)
See Also: → https://bugzilla.mozilla.org/show_bug.cgi?id=1393120
Whiteboard: [qf] → [qf:f61][qf:p3]
I wonder - there seem to be tons of reports of high-profile sites beeing slow: WhatsApp-Web, Facebook, Outlook.com and all lead to issues in layout and extensive time spent in reflows. The WhatsApp-Web report I filed is now I guess 6-12 months old and despite the importance of the content nothing happens. Is there a shortage of developers that are understand the layout code?
Based on comment 3, I am putting this under layout component.
Component: Untriaged → Layout
Product: Firefox → Core
Priority: -- → P2
Whiteboard: [qf:f61][qf:p3] → [qf:p3]
Whiteboard: [qf:p3] → [qf:p3:responsiveness]

Clemens, can you still reproduce? It's possible that some flexbox optimizations over the past year may've helped here.

Blocks: flexbox-perf-issues
Flags: needinfo?(linuxhippy)

I tested this myself (at https://outlook.live.com/mail/inbox ) -- I created an email and pasted in lorem ipsum text a number of times until I had ~13000 characters (to have a decent amount of backscroll/content).

Then I started profiling, mashed my keyboard as fast as I could, and stopped profiling.

The text input felt responsive, and my profile is https://perfht.ml/2Xd6Kxp which doesn't show delays and has hardly any time spent in reflow (only ~150ms total, of a nearly 9 second profile)

This is in comparison to the original profile here which showed ~50% of our time spent in reflow (~26 seconds with reflow in the backtrace, out of ~42 seconds' worth of samples).

So, this is WORKSFORME (whether it's our fix or a fix on the Outlook/Hotmail side). Please reopen if you can still see it, though!

Status: UNCONFIRMED → RESOLVED
Closed: 6 years ago
Resolution: --- → WORKSFORME
Performance Impact: --- → P3
Keywords: perf:responsiveness
Whiteboard: [qf:p3:responsiveness]
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